I would like to share this service with a number of external organisations that also have ArcGIS Server 10.1.
i.e I dont want them hitting my service, but for them to have the ability to easily re-publish the service at their end.

Ideally, I would like to bundle this into a simple installer, which prompts end-user for some admin credentials to ArcGIS Server, and then makes use of a python script to publish the service via the new ArcGIS Server Administration API.